[miR-18a ameliorates inflammation and tissue injury in a mouse model of allergic rhinitis via blocking TLR4/NF-κB pathway].

Objective To investigate the role of microRNA-18a (miR-18a) in the pathogenesis of allergic rhinitis in mice. Methods Twenty-two BALB/c mice were randomly divided into a blank group, a model group and a miR-18a group. Mice in the model group and the miR-18a group were injected intraperitoneally with obumin (OVA) suspension to prepare allergic rhinitis models, and mice in the miR-18a group were simultaneously given lentiviral vector plasmid for overexpression of miR-18a. Allergy symptoms were evaluated by the behavioral score and HE staining. The plasma levels of interleukin-1β (IL-1β), IL-6 and tumor necrosis factor α (TNF-α) were measured by ELISA. The distribution of CD45 cells in nasal mucosa was measured by immunofluorescence histochemistry, and CD45 cells in nasal lavage fluid were measured by flow cytometry. The mRNA expression levels of IL-1β, IL-6 and TNF-α in nasal mucosa tissues were measured by fluorescence quantitative PCR, and the protein expressions of Toll like receptor 4 (TLR4), nuclear factor κB p65 (NF-κB p65), inhibitor of NF-κB α (IκBα) and phosphorylated IκBα (p-IκBα) in nasal mucosa were measured by Western blot analysis. Results Compared with the blank group, the plasma levels of IL-1β, IL-6, and TNF-α in the model group increased significantly. The number of CD45 cells in both nasal mucosa tissue and nasal irrigation fluid increased, and the mRNA levels of IL-1β, IL-6 and TNF-α and the protein expression levels of TLR4, NF-κB p65 and p-IκBα in nasal mucosa increased. Compared with the model group, the plasma levels of IL-1β, IL-6 and TNF-α in the miR-18a group decreased significantly. The number of CD45 cells in both nasal mucosa tissue and nasal lavage fluid decreased, and the mRNA levels of IL-1β, IL-6 and TNF-α and the exprotein expression levels of TLR4, NF-κB p65 and p-IκBα in nasal mucosa decreased. Conclusion miR-18a can inhibit the occurrence and development of allergic rhinitis, and its molecular mechanism is related to the inhibition of TLR4/NF-κB pathway activation.